What is Down syndrome?

Down syndrome is a genetic disorder. It's not an illness or disease.

There are 3 types of Down syndrome:

• Trisomy 21 — most people with Down syndrome have trisomy 21. This means they are born with 3 copies of chromosome 21 in every cell (most people have only 2 copies).
• Translocation Down syndrome — some people with Down syndrome are born with part or all of the chromosome 21 attached to another chromosome.
• Mosaic Down syndrome — this is when only some of the person's cells have an extra copy of chromosome 21.

About 1 in every 1,100 babies born in Australia have Down syndrome. People with Down syndrome often experience specific health challenges.

Most children with Down syndrome go to school and get jobs, just like everyone else. They can live happy, fulfilling lives and are important members of their communities.

What are characteristics of people with Down syndrome?

People with Down syndrome may have:

• some typical physical features
• hearing or visual problems
• some cognitive (mental) difficulties
• some developmental delay

People with Down syndrome will have some level of cognitive impairment, ranging from mild to severe.

What causes Down syndrome?

Most people have 23 pairs of chromosomes in their cells (46 chromosomes in total). People with Down syndrome have an extra chromosome 21. This extra chromosome happens by chance.

Down syndrome happens at conception (the moment when a female egg combines with a male sperm).

The chance of having a baby with Down syndrome increases as the mother gets older.

When should I see my doctor?

If you are pregnant or planning to become pregnant, talk to your doctor about Down syndrome screening.

If your child has Down syndrome, make sure they visit their doctor regularly. This helps to monitor any related health conditions they may have.

How is Down syndrome diagnosed?

Down syndrome is usually diagnosed before birth. There are tests that can be done during your pregnancy to see if your baby has Down syndrome.

Some babies are only diagnosed after birth. If your doctor suspects that your baby has Down syndrome, they will order a blood test for your baby to confirm the diagnosis.

How is Down syndrome treated?

Down syndrome is not an illness or disease, it is a genetic condition and there is no cure or way to treat it.

A healthy diet and physical activity are important for everyone including people with Down syndrome.

If you have Down syndrome, you are more likely to:

• be living with obesity
• have low thyroid hormone levels
• develop osteoporosis

Regular health checks are important so related health conditions can be managed and treated. This includes dental checks.

Early intervention

Children with Down syndrome usually develop more slowly in some areas. Starting early support can help them reach important milestones. Early help can begin any time after they're born, but the sooner it starts, the better.

Living with Down syndrome

Many people with Down syndrome lead independent, happy and healthy lives. Some have jobs and need very little support. They also have friendships and relationships and lead fulfilling personal lives. Others may need more support to help achieve the kind of life most people like to live.

In Australia, the average life expectancy of a person with Down syndrome is 60 years.

Watch this video about the importance of building relationships with health professionals for people with Down syndrome and their families.

What are the complications of Down syndrome?

People with Down syndrome may have a higher chance of health problems, such as:

• problems with their vision
• problems with their hearing
• gut problems
• heart defects
• hypothyroidism
• problems with their bones

About 1 in 2 people with Down syndrome have congenital heart disease. It's important that your newborn with Down syndrome is checked by a paediatric cardiologist. This is a doctor who specialises in looking after the hearts of babies and children.

They may also have lower immunity. This means they may get sick more often, especially in early childhood.

Everyone with Down syndrome has some degree of learning difficulty. They may need speech and language therapy to help them to speak clearly.

Can Down syndrome be prevented?

Down syndrome can’t be prevented. It’s no one’s fault. It can’t be cured. It is not an illness or a disease, it is a genetic condition.

Resources and support

Your doctor is the best place for health support. They can also connect you with other local services.

Read more about prenatal chromosomal screening and caring for a child with Down syndrome.

For more information and support, try these resources:

• Down Syndrome Australia offers more information about Down syndrome. Talk with them by calling 1300 881 935.
• Carer Gateway for emotional and practical services and support for carers.
• Call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak to, 24 hours, 7 days a week.
• The Pregnancy, Birty and Baby video call service allows you to speak face-to-face with a maternal child health nurse. Video call is a free service and is available from 7am to midnight (AET), 7 days a week (including public holidays).

Aboriginal and/or Torres Strait Islanders

You can find out more about Aboriginal and/or Torres Strait Islander pregnancy health on Stronger Bubba Born or watch their video on how to have a safer pregnancy.